PhD Studentship: Constaining carbon and climate system interactions across abrupt global warming ev

Location
United Kingdom
Posted
Jun 30, 2017
Closes
Oct 02, 2017
Organization Type
University and College
Hours
Full Time
Details

Project Highlights

  • Determine how the oceans and global climate evolved across an ancient global warming event
  • Constrain the dominant driver(s) and key feedbacks associated with past environmental change
  • Learn a diverse range of key geochemical, sedimentological and faunal techniques for reconstructing past environments
  • Join a world-class team of scientists working to understand the dynamics of past high-CO2 worlds


Overview
The Eocene epoch (34-56 million years ago; Ma) was characterised by warmer global temperatures and higher atmospheric carbon dioxide levels than today and small or no ice-sheets. These high-CO2 worlds were traditionally considered to be relatively climatically stable but we now know that they were punctuated by numerous transient global warming or ‘hyperthermal’ events[1] that are perhaps our best analogues for anthropogenic change.

One such warming event was the Middle Eocene Climatic Optimum (MECO) which reversed a long-term global cooling trend, ~40 (Ma)[2]. During the MECO global ocean temperatures rose by ~3-5 °C, surface ocean nutrient levels increased, the carbonate compensation depth shoaled by >1 km in all ocean basins, and there were large shifts in both floral and faunal communities[2,3].

However, our inability to reconcile observations with basic carbon cycle theory across the MECO highlights major gaps in our understanding of the link between the climate and carbon cycle over intermediate timescales (~50-500 kyrs)[4]. This is exacerbated by a dearth of records against which to test key hypotheses. For instance, we still have very poor constraints on the rate and timing of carbon input, the magnitude of tropical and high northern latitude temperature change and the driver(s) of the environmental change (e.g., volcanism vs. ocean circulation changes)[4]. This project will fill these critical gaps in our understanding of the global climate system during past high-CO2 intervals and ultimately help to reduce uncertainty related to predicting future climatic changes.

 

References

[1] Sexton et al., Nature, 471, 349-352 (2011).
[2]Bohaty et al., Paleoceanography, 24, doi:10.1029/2008PA001676 (2009).
[3] Edgar et al., Palaeogeography, Palaeoclimatology, Palaeoecology, 297, 670-682 (2010).
[4] Sluijs et al., Nature Geoscience, 6, 429-433 (2013).